The invention concerns a device for holding a tool so that it is continuously adjustable on a spindle that can be driven on a tooling machine, wherein the tool is attached to a tool holder so it can be changed. The tool holder is mounted in a housing so it can swivel on the axis of rotation of the tool holder, which runs at an angle, preferably a right angle, to the axis of rotation of the tool spindle.
In practice, so-called flat turntables for continuous adjustment of the tool holder on a tooling machine, for example a tool rest, are known. These flat turntables have a slide moved by translation whereby the tool can be moved on the workpiece. To equalize the imbalances caused by centrifugal force that occur when the table is moved, the known flat turntables have equalization with a table going the other way or with counterweights.
The disadvantage of these known devices for holding a tool so it is continuously adjustable on a spindle of a tooling machine is that, on one hand, only a translational movement of the tool can take place and, on the other hand, because of the remaining imbalances and centrifugal forces, continuous adjustment is not possible in the xcexcm range at high tooling rpm.
Another way of continuously adjusting a tool holder is shown in FR 459 327. This publication shows a tool holder with all the features in the preamble, as it is formulated in claim 1.
Here, the tool holder is swiveled by turning a set screw whose threads come in contact with a threaded section molded on one end of a tool holder mounted so it can swivel in a housing.
This type of adjustment option has the disadvantage that it must be activated manually and the tooling machine must be stopped completely for this. Also, it is difficult to get the position required for adjustment in the xcexcm range with such a manually activated adjustment screw.
The problem of the invention is to create a device for holding a tool so that it is continuously adjustable on a spindle that can be driven on a tooling machine that makes it possible to adjust the tool in the xcexcm range in many ways with almost complete equalization of the imbalances caused by centrifugal force.
The solution to this problem in the invention is characterized by the fact that the tool holder can be swiveled in the housing by a motor, magnetically or by a pressurized drive.
Swiveling the tool holder on an axis that intersects the axis of rotation of the tool spindle at an angle, preferably a right angle, makes it possible to equalize the masses of the tool holder and the tool lying on both sides of the swivel axes in such a way that the mass center of gravity lies at the point of intersection of the swivel axis and the axis of rotation, so that when the tool holder mounted adjustably in the housing rotates, no imbalance occurs due to centrifugal force. Only because of this prevention of imbalances due to centrifugal force is it possible to adjust the tool holder and thus the tool finely in such a way that changes in movement are possible in the xcexcm range, which is in turn the precondition for continuous adjustment, especially by CNC control.
Because of the swivel mounting of the tool holder, it is also possible with the device in the invention to make not only purely translational movements of the tool.
The invention proposes that the tool holder can be swiveled in the housing by a motor, magnetically or by a pressurized drive. In one preferred form of embodiment of the invention, the tool holder has a swivel piston which is arranged in a cylinder chamber of the housing and can be activated on opposite sides with a pressure medium. This design as a pressure-activated swivel piston permits very fine, easy swiveling of the tool holder at high force by recirculating the pressure medium.
In one practical form of embodiment of the tool holder with a swivel piston, the tool holder is designed like a disk with swivel pistons molded in the form of an annular section, which is arranged in an annular section-shaped cylinder chamber of the housing. In this form of embodiment, the annular-section-shaped swivel piston is the counterweight to the actual tool holder plus tool, so that there is in turn an equalization of masses.
The invention also proposes that the generating surfaces and front surfaces of the tool holder and the swivel piston be designed as leading surfaces opposite the housing. In this design, the generating surfaces and front surfaces represent sealing surfaces at the same time, if a drive with a pressure medium is provided as the drive for the swivel piston.
To allow the tool holder, and hence the tool, to be adjusted with no play and perfect translation, in one preferred form of embodiment of the invention, a direct measurement system is arranged between the housing and the tool holder. In this context, direct means that the measurement system directly records the adjustment of the tool holder with no intermediate connection of other transmission elements.
Finally, the invention proposes that the tool be attached and detachable, so that it cannot turn on the tool holder by means of a repeating precision fast-change system. Using such a fast-change system ensures that, on one hand, the tool can be changed fully automatically without long idle times and, on the other hand, the repeating precision, non-turning attachment of the tool guarantees that because of the known tool geometries, the tooling can be continued with no realignment or measurement of the tool.
According to one practical form of embodiment of the invention, gaseous and/or liquid media can be added to the fast-change tool system and/or the tool through the tool holder for cooling, cutting and cleaning purposes. These gaseous and/or liquid media can be, for example, compressed air for cleaning, lubricating oil for cutting and cooling, or nitrogen for cooling.